DSpace Collection:

Long-term iron-bentonite interaction in a water-saturated room-temperature environment: Advancing for safety of metal waste containment in the geosphere

2026-03-13T12:04:36Z

Title: Long-term iron-bentonite interaction in a water-saturated room-temperature environment: Advancing for safety of metal waste containment in the geosphere Authors: Turrero, María J.; Torres, Elena; Martín, Pedro L.; Fernandez, Raúl; Ruiz, Ana I.; Ortega, Almudena; Garralón, Antonio; Notario Collado, Belén; Mota, Carlos; Cuevas, Jaime F. Abstract: Corrosion of C-steel containers may affect the long-term safety of deep geological repositories. To address uncertainties, the FeMo experiment was initiated in 2007 to evaluate iron mobility and bentonite alteration under aerobic conditions, granite-type water saturation, high corrosion rates, and room temperature. After 15 years, the experiment was dismantled for comprehensive analysis. The Fe-bentonite interface exhibited a multi-layered structure, with a black iron stripe and a brown-stained bentonite zone (2–5 mm thick). Altered iron comprised magnetite (50%), goethite (25%), siderite (5%), and ≈20% wt. metallic iron. The brown zone contained montmorillonite, cristobalite, feldspar, quartz, magnetite, goethite, lepidocrocite, and minor siderite. Chemical zonation of Fe, Mg, and Ca was observed within the first 0.5 mm from the interface. Iron penetrated up to 2–3 mm into the bentonite. Evidence of a trioctahedral clay component mixed with montmorillonite was found. Magnetite, carbonates, and Mg-rich clays precipitated under alkaline reducing conditions during the oxic-anoxic transient at the interface (<1 mm). This study's results are not only relevant for guaranteeing radioactive waste repository safety but also to assess other heavy metal containment strategies in other environmental applications, such as mines and landfills.

Iron-Bentonite Interaction in a Water-Saturated Low Temperature Environment: Mineralogy and Microstructure

2026-03-13T12:04:54Z

Title: Iron-Bentonite Interaction in a Water-Saturated Low Temperature Environment: Mineralogy and Microstructure Authors: Turrero, M.J.; Torres, E.; Martín, P.L.; Fernández, R.; Ruiz, A.I.; Ortega Martínez, Ana Isabel; Notario Collado, Belén; Mota, C.; Cuevas, J.F. Abstract: In the context of the NF-PRO project [1], an iron-FEBEX bentonite interaction experiment (FeMo) was initiated at CIEMAT in 2008 with the aim of evaluating iron mobility and bentonite alteration considering a conservative scenario: (i) saturated conditions, (ii) aerobic initial conditions, (iii) high corrosion rates (use of iron powder), and (iv) room temperature. FeMo was analyzed in the context of the European EURAD-ACED project after 15 years of operation (until 2023). Description: Poster presented at 9th Clay Conference, Hannover (Alemania) 25 – 28 Noviembre 2024

Documentation of Artistic Production Patterns and Alteration Pathologies in Glass and Glazes through Micro Computed Tomography (µ - CT)

2026-03-13T12:04:24Z

Title: Documentation of Artistic Production Patterns and Alteration Pathologies in Glass and Glazes through Micro Computed Tomography (µ - CT) Authors: Palomar, T.; Rodrigues, A.; Machado, C.; Pulido-Valente, F.; Coutinho, I.; Gomes, F.B.; Coentro, S.; Vilarigues, M.; Notario Collado, Belén Abstract: Glass and ceramic objects are intrinsically connected to their decorations, which can be very different according to their chronology and function. The most common decoration in glass was to use two different coloured glasses, such as in core-formed vases or filigree and millefiori glass canes. Surface paintings such as enamels, grisailles, sanguine, and cold paintings are very common in stained-glass windows, reverse paintings, and magic lanterns’ slides. And, finally, glass can also be decorated with induced crystallization and post-productional treatments such as white and opaque red glass, yellow silver staining, or coloured glazes, used in stained-glass windows, glassware, and ceramics. In this work, developed through a FIXLAB action (H2020 project IPERION HS), we used micro-computed tomography (μ-CT) to analyse the surface and the internal structure of different pieces (stained glass, glass beads, porcelain, tiles, etc.) in a non-destructive way. The objective of this project was to know how the objects were produced and their alteration state through the characterization of surface decorative layers, the identification of the crystalline particles, and the evaluation of alteration pathologies. Results showed that decorations with a different chemical composition were observed clearly, even in very altered glasses, as well as the bubbles produced during manufacturing. The thickness of the decorative layer in pieces from stained-glass windows and glazed ceramic was also estimated. This technique was especially interesting to study the distribution of inclusions and porous in ceramic pastes and mortars. It is, therefore, a very useful and promising technique to characterize the decoration, the alteration pathologies and production patterns in different glasses, glazes and ceramics. Description: Ponencia presentada en: TechnoHeritage 2024, Santiago de Compostela (España) 25 – 27 Septiembre 2024

To what extent high resolution mCT-scanning of hominin fossil remains may impact ESR and Radiocarbon dating results?

2026-02-20T08:18:57Z

Title: To what extent high resolution mCT-scanning of hominin fossil remains may impact ESR and Radiocarbon dating results? Authors: Duval, Mathieu; Wood, R.; Martín-Francés, Laura Abstract: In palaeoanthropological research, the study of human fossils is conditioned by the necessity to cause minimum damage to these rare and valuable remains. In this context, micro-computerized tomography (µCT) scanning of fossils is nowadays routinely used to record a high resolution 3D reconstruction of samples, enabling to obtain critical information about the morphology or internal structure of the fossil, and create a digital archive of fossils that may be destructively analysed later. While these destructive analyses may be carried out for a wide range of purposes, including palaeodiet or palaeoenvironment reconstructions, mobility studies, ancient DNA and Geochronology, the potential impact of µCT scanning on the analytical results has been very little investigated so far. In the present lecture, we present the most recent results on our methodological investigations focused on Radiocarbon and Electron Spin Resonance (ESR) dating, which can both be directly applied to fossils. While Radiocarbon dating is the most widely used for any fossils younger than 50 ka, ESR can take over for older specimens. In particular, the latter has become very popular over the last couple of decades, with the dating of several key human fossils, such as those from Jebel Irhoud, (Morocco), Atapuerca Gran Dolina (Spain), Rising Star (South Africa) or Milsiya (Israel). It is therefore crucial to establish whether µCT scanning has a negative impact on the associated ESR and Radiocarbon analysis, and, if any, to determine how this impact can be reduced. With this purpose in mind, we carried out a series of tests with various conventional µCT instruments and using a range of acquisition parameters. The main experimental results will be presented and discussed in this talk, as well as their implications for palaeoanthropological research, taking a few recent case studies as examples. Description: Ponencia presentada en: 44th International Symposium on Archaeometry, Melbourne, Australia, 27-31/05/2024